Phylogenetic positions of rust fungi parasitic on ferns: Evidence from 18S rDNA sequence analysis

Abstract

Molecular phylogenetic analyses of fern rusts were carried out based on 18S rDNA sequences. We sequenced the 18S rDNAs of fern rusts (Hyalopsora polypodii and Uredinopsis intermedia) and non-fern rusts (Aecidium epimedii, Coleosporium asterum, Ochropsora kraunhiae, Puccinia suzutake and Physopella ampelopsidis) and analyzed their phylogenetic relationships with other members of the Urediniomycetes. Our bootstrapped neighbor-joining tree obtained from these analyses showed that rust fungi were apparently monophyletic at high confidence level (100% bootstrap confidence). In this molecular phylogenetic tree, the two fern rusts did not occupy the basal position within the rust fungal lineage and did not form a monophyletic lineage. Two species of the Cronartiaceae (Peridermium harknessii, Cronartium ribicola) and one species of the Coleosporiaceae (Coleosporium asterum) grouped with the fern rusts. Therefore, our results suggested that the two fern rusts were not primitive. On the other hand, Mixia osmundae, which is parasitic on the primitive fern Osmunda, was phylogenetically far from the fern rusts.

Relatedness, phylogeny, and evolution of the fungi

“…The scale bar indicates one base change per 100 nucleotide positions. For sequence references, see and Sjamsuridzal et al (1997Sjamsuridzal et al ( , 1999 , and this is a reason for using hemiascomycetes, plectomycetes and pyrenomycetes as informal names until the respective groups are redefined or renamed ). However, the class level names "Archiascomycetes," Hemiascomycetes, and Euascomycetes have been adopted in yeast classification by Kurtzman (1998b (Goto and Sugiyama, 1970), and its research history has been fully outlined by .…”

“…However, recent molecular phylogenetic data demand re-evaluation of the basidial morphology as a taxonomic character (e.g., Suh and Sugiyama, 1994;Taylor, 1993, 1995a, b). Our targets for molecular basidiomycete phylogenetics are now extended to the whole urediniomycetes (Sjamsuridzal et al, 1999).…”

Mycosphaerellaceous fungi and new species of Venustosynnema and Zasmidium on ferns and fern allies in Taiwan

“…The most recent overview of saprobic, parasitic and symbiotic fungi associated with ferns was published by Mehltreter (2010). The relationship between rust fungi and ferns was first to attract the attention of phylogenetic mycologists (see Sjamsuridzal et al 1999 and references therein). Molecular analyses indicated that fern rusts were not basal to the rusts on seed plants (Sjamsuridzal et al 1999).…”

“…The relationship between rust fungi and ferns was first to attract the attention of phylogenetic mycologists (see Sjamsuridzal et al 1999 and references therein). Molecular analyses indicated that fern rusts were not basal to the rusts on seed plants (Sjamsuridzal et al 1999). In contrast to the rust fungi, which are biotrophs on their host plants, evidence for parasitism by other fungi on ferns is often not clear or is only concluded from field observations.…”

Phylogenetic position of Mixia osmundae inferred from 28S rDNA comparison.

“…The Urediniomycetes group is divided into four major clusters: the Erythrobasidium/Sakaguchia lineage, the Agaricostibum/Bensingtonia lineage, the Rhodosporidium/Sporidiobolus lineage, and the rusts/ Helicobasidium lineage (Sjamsuridzal et al, 1999;Swann and Taylor, 1995). However, the phylogenetic placement of M. osmundae within the Urediniomycetes group has been uncertain (Hamamoto and Nakase, 2000;Sjamsuridzal et al, 1999;Swann et al, 2001). Fell et al (2000) sequenced the D1/D2 region of the 28S rDNA from most basidiomycetous yeasts and compared them.…”